build(deps): bump .devcontainer from 190f80b to c7f9cd6

Bumps [.devcontainer](https://github.com/EffectiveRange/devcontainer-defs) from `190f80b` to `c7f9cd6`.
- [Commits](EffectiveRange/devcontainer-defs@190f80b...c7f9cd6)

---
updated-dependencies:
- dependency-name: ".devcontainer"
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>